Lecture Exam 1 Flashcards
Fibrous Connective Tissue - Loose Connective Tissue
- Has a lot of matrix with fewer fibers – more ground substance
- Areolar Tissue
- Reticular Tissue
Fibrous Connective Tissue - Dense Connective Tissue
- Lots of fibers with little ground substance
- Dense Regular Connective Tissue
- Dense Irregular Connective Tissue
Loose Connective Tissue: Areolar Tissue
Structure:
- Loosely organized fibers
- Contains all 6 cell types (fibroblasts, plasma cells, adipose, etc)
- Cells are spaced out
- Fibers are not in any direction, overlapping themselves
- Spread
- Has a lot of ground substance – a lot of fibroblasts
- Thicker fibers – collagen
- Smaller fibers - elastin
Function:
- Tissue under epithelium
- Contains blood vessels & nerves that nourish the epithelium
- Ability to pull in different direction – a lot of collagen fibers
Loose Connective Tissue: Reticular Tissue
Structure:
- A lot of ground substance
- Ground substance is full of blood cells (Typically, red blood cells)
- Mesh of reticular fibers (tend to look like spiderwebs) and fibroblasts
Function:
- Resists stretch in many directions
- Provides framework for organs in immune system (bone marrow, spine, thymus, krypton nodes)
Dense Connective Tissue: Dense Regular Connective Tissue
Structure:
- Has a lot of fibers
- Also called white fibers
- Tightly packed, usually parallel, collagen fibers
- Few cells that make collagen
Function:
- Make up tendons & ligaments
- Resist pull in a single direction
- Flexible in a side-to-side direction
Dense Connective Tissue: Dense Irregular Connective Tissue
Structure:
- Lots of fibers, thick bundles of collagen, a few cells and very little ground substance
- Collagen bundles are oriented in many different directions
Function:
- Resist pull in many directions
- Stronger than reticular
- Find it in dermis of skin (lower)
- Keeps skin from detaching
Adipose Tissue
Structure:
- Fat tissue
- Made of primarily cells called adipocytes
- Usually In areolar, reticular, blood cells –tissue surround and enter the adipose tissue
Function:
- Store triglycerides (lipids)
- Release triglycerides when the body needs energy
- Also acts as cushion for organs
White Fat
Structure:
- Adipocytes grow in size as they store more triglycerides
- Triglycerides are stored in the center of the cells
- If one has a lot of triglycerides – cytoplasm and nucleus are pushed to the sides
Location and Function:
- More abundant
- Thermal insulation
- Anchors and cushions your organs
- Contributes to body contours
- Stores and releases triglycerides as needed
- Under all surfaces of the body and around organs
Brown Fat
Structure:
- Stores triglycerides in multiple globules instead of one large one
- Lots of blood vessels
- Many mitochondria
Location and Function:
- Location – in young babies and children (very abundant) – fat pads in shoulders, upper back and around the kidneys – important to keep infants warm
- Adults have it in the same place but its smaller
- Generates heat
- Mitochondria don’t make ATP from fat- release it as heat
- Abundant in hibernating animals
General Cartilage Characteristics
- Stiff connective tissue with a flexible, rubbery matrix
- Gives its organs their structure and support (ex. Shape of nose)
Formation of Cartilage
- Chondroblasts
- Matrix
- Chondrocytes
- Lacunae
Cartilage - chondroblasts
- Cells that make matrix of cartilage
- Found outside of cartilage
Cartilage - Matrix
- Rich in GAGs and collagen
- Chondroblasts make matrix
- Lacks blood vessels
Cartilage - Chondrocytes
- Chondroblast that have gotten trapped in their own matrix
- No longer make matrix – alive but not productive
Cartilage - Lacunae
Chambers that hold chondrocytes
Matrix and Repair of Cartilage
- Matrix (GAGs and collagen)
- Lack of Capillaries (No blood in tissue – nourished from outside)
- Slow Repair (Repairs slowly if at all)
- Must repair from outside in
Cartilage Growth - Perichondrium
- Membrane outside of cartilage
- Contains blood vessels
Cartilage Growth - Reserve Chondroblasts
- Chondroblasts in mature cartilage that divide to replace cartilage tissue
- Under perichondrium, near blood
Cartilage Types
- all have chondrocytes in lacune
- Hyaline (Matrix is clear and glassy)
- Elastic (Has many elastic fibers)
- Fibrocartilage (Matrix has many collagen fibers)
Hyaline Cartilage
Structure:
- Chondrocytes in lacunae
- Clear glossy matrix
- Made of GAGs with think and fine collagen
Function:
- Hard cartilage
- Doesn’t have a lot of stretch
- Rings around the trachea – holds trachea open
- Placeholder for bones in an infant and early childhood
Elastic Cartilage
Structure:
- Chondrocytes in lacunae
- Matrix has GAGs and a visible array of elastic fibers
Function:
- Stretchy cartilage
- Found in ears, nose
Fibrocartilage
Structure:
- Heavy and abundant collagen fibers in matrix
- Chondrocytes in lacunae
Function:
- Springy
- Good padding
- Makes up intervertebral disc – pads area between spinal cord
Bone Characteristics
Osseous Tissue - Aka bone:
- Hard, calcified connective tissue
- Composes skeleton
Other Components:
- Osseous tissue – only base tissue
- Also contains cartilage, bone marrow, dense irregular connective tissue, and others to make up the bone organs
Types of Osseous Tissue - Spongy Bone
- Looks like a sponge
- Has many openings and delicate slippers
- Inside of the bone
- Protects bone from being too heavy
Types of Osseous Tissue - Compact Bone
- Hardened solid bone tissue
- Very dense with no spaces
- Makes up external spaces of bone
Compact Bone Structure - Central Canal
- tree trunk
- Middle of each tree trunk
- Extend down the entirety of the bone
- Openings for blood vessels and nerves (makes it able to repair quickly)
Compact Bone Structure - Lamellae
- Concentric rings around each central – layers if bone tissue around each canal (that deposit)
- Separated by collagen fibers
- tree trunk
Compact Bone Structure - Osteon
- tree trunk
- The entirety of the tree – central canal with all its rings (the whole structure)
Compact Bone Structure - Lacunae
- Sitting around lamella – in bone, lacunae hold osteocytes (mature bone cells)
Compact Bone Structure - Canaliculi
- Channels between lacunae – connect osteocytes to each other
Compact Bone Structure - Periosteum
- Membrane on outside of bone
- Holds osteoblast underneath
- makes bone matrix
- Osteoblast get trapped in lacunae - becomes osteocytes
Bone Matrix
Collagen:
- Between lamellae
- Allow bone to bend, not stretch
Minerals:
- Calcium and phosphates
- Makes bone matrix hard
Fluid Connective Tissue - Blood
Composition:
- Cells in a liquid matrix (plasma)
Function:
- Carry nutrients to body and wastes away from body
Nervous Tissue
Neurons:
- Large cells that signal in nervous tissue
Neuroglia:
- Smaller cells that support the neurons
Function:
- Signal for communication in body
Muscular Tissue Types
Features:
- Contractile – cells shorten
Types - 3:
- Skeletal – attach bones (voluntary signal)
- Cardiac – heart (involuntary signal)
- Smooth – organs (involuntary signal)
Skeletal Muscle
Structure:
- Long cells with several nuclei in them
- Cells are unbranched – single line
- Striated (light and dark bands)
Function:
- Attached to bones
- Under voluntary control
Cardiac Muscle
Structure:
- Striated, single cells, separated by intercalated discs (dark bands)
- Cells are branched
Function:
- Only in heart, involuntary
Smooth Muscle
Structure:
- Non striated
- Spindle-shaped
- One nucleus
Function:
- Are in blood vessels and organs
- Contract involuntarily
Connections Between Cells - Anchorage to Other Cells
- Cells must be attached to other cells to be cohesive
Connections Between Cells - Anchorage to Matrix
- ALSO - Cells must be attached to matrix to be cohesive
Types of Cell Junctions
- Tight Junctions
- Desmosomes
- Gap Junctions
Tight Junctions
- Zipper like
- Attach cells tightly
- Stop material from getting between cells
Desmosomes
- Buttons
- Attach cells loosely
- Material can get between
Gap Junctions
- Doors
- Pores between cells
- Allows cytoplasm to pass
Gland
Definition:
- Cell within tan organ that secretes substances
Secretions:
- Products that’s useful for the body
- Excretion waste product
Structure:
- Gland is made of mostly epithelial tissue, usually simple cuboidal epithelium
- Often connected to a channel called a duct – releases a products to surface
Exocrine Glands
- Secretes products through a duct to the surface of the body
- Exo – outside (skin, digestive system or mucous membrane)
Endocrine Glands
- Inside
- Secretes products into the bloodstreams
- Thyroid
Secretion of Serous Glands
- Produce a watery fluid with enzymes
- Sweat glands
Secretion of Mucous glands
- Produce mucus – thick slimy fluid
- Lacs enzymes but for lubrications
- Traps debris
Secretion of Mixed Glands
- Produce serous fluid and mucus
Modes of Exocrine Gland Secretion
Merocrine:
- Produce secretions inside the cell,
- Sweat
- release them by exocytosis into the environment
Apocrine:
- secrete fat from droplets that bud from cell surface (mammary glands)
Holocrine:
- release wide cells that then break down and release products (sebaceous glands )
Body Membranes - Cutaneous membrane
Skin – made of epidermis and dermis
Body Membranes – Mucous membrane
- Line areas of body that lead to outside mouth, nose, throat, urinary, digestive
- Produce mucus
Body Membranes – Serous membrane
- Line internal membranes – linings of body cavities
- Pericardium, Pleura, peritoneum
Body Membranes - Endothelium
Internal lining of blood vessels
Integumentary System
Skin:
- Cutaneous membrane outside body
- Sensory organ - touch, temperature etc.
Hair:
- Dead tissue/filaments that extend from most parts of the skin
Nails:
- Covers tips of the digits for primarily protection
- Allows to dig into
Associated Glands:
- Sweat, subclades, others
The Skin (Integument)
Location:
- Covers exterior surface of body and some interior surfaces
Quantity:
- 15% of body weights
- Body’s largest and heaviest organ
Layers of the Skin
- Epidermis
- Dermis
- Hypodermis
Epidermis - skin
- On the outside
- Thick layer
- Stratified squamous epithelium
Dermis - Skin
- Under epidermis
- Made of connective tissue
- Alveolar, reticular, dense irregular.
- Contains blood vessels and nerves
Hypodermis - skin
- Not part of the skin
- contains connective tissue – lots of adipose tissue to pad skin (thermal insulation to skin)
Thin Skin
- Rest of body
- Thinner epidermis
- Has hair follicles, sebaceous glands, sweat glands
- Loosely organized.
Thick Skin
- Palms, soles of feet, fingers, toes
- Sweat glands but lack hair follicles and sebaceous glands
- Thick layer of epidermis
- Epidermis tightly compacted
Functions of the Skin
- Resistance to Trauma and Infection
- Other Barriers
- Vitamin D Synthesis
- Sensation
- Thermoregulation
- Nonverbal Communication
Functions of the Skin - Resistance to Trauma and Infection
- Has many mechanisms to prevent and heal from trauma
- Skin is waterproof
- Nutrient poor
- Microbes do not grow well on skin
Functions of the Skin - Other Barriers
- Barrier to water – prevents absorption of outside water and the loss of internal water
- Impermeable to most drugs and most toxins
Functions of the Skin - Vitamin D Synthesis
Carries out the first step of vitamin D synthesis (requires sunlight)
Functions of the Skin - Sensation
Sense of touch and a lot of other senses are carried out by skin
Functions of the Skin - Thermoregulation
- Sense of hot and cold is in the skin
- Blood vessels near the skin constrict to stop heat loss when cold (skin turns blue or pale when cold)
Functions of the Skin - Nonverbal Communication
- Muscles that attach to skin convey emotion
- Self image
The Epidermis
Outside of skin
Composition:
- Stratified squamous epithelium
- Keratinized – surface contains intermediate filament called keratin
Nutrition:
- Epidermis lacks blood vessels and nerves – skin surface is often dead
Blood Vessels and Nerves:
- In dermis – nourish and give sensation from underneath epidermis (base of epidermis is alive)
Cells of the Epidermis
- Stem Cells
- Keratinocytes
- Melanocytes
- Tactile cells
- Dendritic cells
Epidermis - Stem Cells
- Only cells in the epidermis that can divide
- Sit on the basement membrane
- Become keratinocytes
Epidermis - Keratinocytes
- Normal cells making up stratified squamous epithelium – make keratin
Epidermis - Melanocytes
- Only at the basement membrane
- Synthesis brown to black pigment melanin – secrete melanin to nearby cells
- Keratinocytes uptake melanin and use it to shield their nuclei form UV light
Epidermis - Tactile Cells
- Very few cells
- Receptors for very light touch
- Connected to a nerve
Epidermis - Dendritic Cells
- In epidermis
- Immune cells that alert the immune system for any invaders
Layers of the Epidermis
- Stratum basale
- Stratum Spinosum
- Stratum Granulosum
- Stratum Lucidum
- Stratum Corneum
Layers of the Epidermis - Stratum basale
- A layer of cuboidal epithelium at the basement membrane
- Melanocytes, tactile cells, stem cells inside – where stem cells divide to make keratinocytes
Layers of the Epidermis - Stratum Spinosum
- Several layers of living keratinocytes
- Usually, thickest
Layers of the Epidermis - Stratum Granulosum
- Three to five layers of very flat keratinocytes
- See more of it in thick cells
- Stains dark because the keratinocytes are starting to die and produce keratohyalin granules
Layers of the Epidermis - Stratum Lucidum
- Only in very thick skin
- Made of keratinocytes that are packed with clear protein eleidin
- Cells have no nuclei or organelles – very clear
Layers of the Epidermis - Stratum Corneum
- Outside layer of the skin
- Made of 30 layers of dead, scaly, keratinized cells
- Durable surface – strong and abrasion resistant
- Surface sloughs off
The Dermis
Composition:
- Primarily connective tissue
- Lots of collagen
- Also, reticular and elastic fibers
Blood Vessels, Nerves and Glands:
- Has many blood vessels, nerves, glands – well nourished
Muscles:
- Some skeletal muscles
- Attached to dermis – produce expressions, wrinkles
Dermal Papillae:
- Wavy boundary between epidermis and dermis – make fingerprints
Layers of the Dermis - Papillary Layer
- Upper dermis near the dermal papillae
- Made of areolar tissue
Layers of the Dermis - Reticular Layer
- Lower layer
- Made of dense irregular connective tissue
- Has collagen, sometimes reticular fibers, some adipocytes
- Stretch marks
The Hypodermis
Subcutaneous tissue
Tissue:
- Made of areolar and adipose tissue
Function:
- Contains subcutaneous fat – energy reservoir and thermal insulation
Skin Color
- Melanin
- Melanocytes
- Forms of melanin
Skin Color - Melanin
- Dark brown/black pigment made by melanocytes – scatter to surrounding keratinocytes
- Shields nuclei from UV lights
Skin Color - Melanocytes
- Cells that produce melanin
- melanocytes are roughly equivalent in all skin colors but produce more melanin in people with darker skin.
Skin Color - Forms of melanin
- 2 forms of melanin (Eumelanin and pheomelanin)
- Eumelanin - brownish black
- Pheomelanin – reddish yellow
Dark Skin:
- More melanin
- breaks down more slowly
Light Skin:
- Less melanin
- Breaks down easier/more quickly
Other Skin Color Considerations - Suntan
- Over production of melanin when exposed to the sun (UV – light)
Other Skin Color Considerations - Hemoglobin
Imparts a reddish color to skin (in blood)
Other Skin Color Considerations - Carotene
Imparts a yellow color to skin – in yellow/orange vegetables
Other Skin Color Considerations - Cyanosis
Blue color of skin from lack of oxygen
Other Skin Color Considerations - Erythema
- Abnormal redness from exercise or heat
- Because blood vessels near the skin are more open to release your heat
Other Skin Color Considerations - Pallor
Pale color – no or little blood flow to the skin
Other Skin Color Considerations - Albinism
- Lack of melanin in the skin
- Genetic phenomenon
Other Skin Color Considerations - Jaundice
- Yellow skin and yellow eyes
- Yellow correlation caused by a malfunction in the liver
- Happens in babies and is an accumulation of bilirubin in skin
Other Skin Color Considerations - Hematoma
- Bruise – see clothed blood through your skin
- Injury in dermis
Skin Markings - Friction Ridges
- Fingerprints
- From dermal pupillae
- Occur early on - just before birth
- For more grip
Skin Markings - Flexion Lines
- Lines on palms, wrists, ankles etc.
- Folds of deeper connective tissue in areas where you bend an appendage
- Protects the fold
Skin Markings - Moles
-Elevated patch of melanized skin - often has hair
Skin Markings - Freckles
- Aggregate of melanized keratinocytes
- Flat patches
- Sometimes because of sun exposure
- Sometimes inherited
Skin Markings - Hemangioma
Patch of skin which is discolored by benign tumors of the blood capillaries (Pictures)
Hair – aka pilus
Composition:
- Slender filament of keratinized cells
Location:
- Grows through a tub called a hair follicle
- In the dermis but pierce the epidermis and goes out
Types of Hair
- Lanugo
- Vellus Hair
- Terminal Hair
Types of Hair - Lanugo
Fine, downy, unpigmented hair on a fetus and a newborn
Types of Hair - Vellus Hair
- Fine and pale hair in young children (except for the eyebrows, eyelashes and scalp
- 2/3 of hair in women
- 1/10 of hair in men
Types of Hair - Terminal Hair
- Long, pigmented hair
- Eyebrows, eyelashes and scalp of all people
- Males and females – grows in other places and forms axillary and pubic hair
- Males – forms facial hair, trunk and limbs (has more hair because of testosterone
Structure of a Hair Follicle
Melanized (contain pheomelanin and/or eumelanin)
Shaft:
- Above the skin
- Keratinized dead cells
- Oldest hair cells
Root:
- Beneath the skin
- Most of it is dead and made of keratinized dead cells (except the bulb which is living
Bulb:
- Dilation at base of hair in dermis – living cells with a blood supply
Layers of Hair - Medulla
- Inside of the hair
- Contains packed cells with melanin in it
- Core of cells around an open-air space
Layers of Hair - Cortex
- Outside of hair
- Many layers of melanized and keratinized cells
Layers of Hair - Cuticle
- Several layers of very thin, scaly cells that overlap
- Very outside of the hair
Layers of Hair
- Medulla
- Cortex
- Cuticle
Hair Follicle
Tube around the hair
Epithelial Root Sheath:
- Extension of epidermis
- Carries around entire hair
- Touches hair
- Divides at base to make new hair
Connective Tissue Root Sheath:
- Below epithelial
- Root sheath – collagen, support epithelial root sheat
Hair Receptors
Function:
- Neurons that encase each hair – sense movement of the hair
Piloerector Muscle – arrector pili muscle:
- Muscle that responds to activation of hair receptors by making hair stand or end
Hair Receptors
Function:
- Neurons that encase each hair – sense movement of the hair
Piloerector Muscle – arrector pili muscle:
- Muscle that responds to activation of hair receptors by making hair stand or end
Nails
Composition:
- Clear, hard derivatives of stratum corneum
- Thin, dead, scaly cells packed together and filled with hard keratin
Function:
- Hard, picking apart food, other manipulation
- Allow for more sensitive fingertips
Parts of a Nail
Nail Plate:
- Hard part of the nail
- Free edge over the tip and the part you see over skin (part that you paint)
Nail Fold:
- Skin that rises around nail
Nail Bed:
- Skin that underlies the nail (under the nail plate)
- Layer of epidermis – hyponychium
Nail Matrix:
- Proximal end of the nail
- Where mitosis of the nail occurs
- Layer of stratum basale
Cuticle:
- Protective layer of skin
Cutaneous Glands
Merocrine Sweat Glands
- Whole skin
Apocrine Sweat Glands
- Pheromone release
- Armpits – pubic
Sebaceous Glands
- Hair follicles – for lubrication
Ceruminous Glands
- Ear
Mammary Glands
- In breasts
Apocrine Sweat Glands
- Actually, merocrine secretion (thin watery fluid)
- Pheromones for sexual attraction – pleasantly fragrant
- When metabolized by skin bacteria – start to smell
- Arise in puberty
Location:
- Some in groin, anal region, axilla, areola, beard area in mature males
Structure and Secretion:
- Connected to hair follicles
- Ducts secrete the products out of the hair follicle
Merocrine Sweat Glands
Location:
- Distributed over the whole body
Structure and Secretion:
- Made of a ball of cells with a duct leading to skin surface
- Not connected to a hair follicle
- Merocrine secretions of water and salt – evaporate, cools body down
Myoepithelial Cells
Location:
- Both in apocrine and merocrine sweat glands
- In deep end of gland
Function:
- Contract to force sweat up
Sebaceous Glands
Structure:
- Holocrine glands
- Not typically sweat glands
- Multiple layers of cuboidal epithelium
- Always connected to a hair follicle
Secretion:
- Known as sebum
- Holocrine secretion – make an oily secretion that lubricates your hair (keeping it from being dry and cracked)
- Distributed by a hair brush
Ceruminous Glands
Location:
- In the ear canal
- Yellow, waxy secretion
- Combines with sebum and dead cells to form earwax
Function:
- Earwax - known as cerumen – keeps your eardrum pliable, waterproofs ear, kills bacteria, coats hairs
Mammary Glands
Location:
- Develop in female pregnancy
- Stay throughout breast feeding
Function:
- Modified apocrine sweat glands – produce milk
Burns
Causes:
- Fire, chemical spills, hot bath water, sunlight, radiation, electric shocks, chemical
Fatalities:
- Fluid loss, infection, toxic effects of the dead skin
Eschar:
- Burned, dead tissue
- Food for bacteria
First-Degree Burn
Factors:
- Only damage epidermis
- Redness, slight edema or swelling, some pain
Healing:
- Heal in a few days without help
- Most sunburns fall into this
Second-Degree Burn
Factors:
- Involves dermis and part of epidermis
- Leaves a chunk of dermis intact
- Red, tan, white, blistered and painful
Healing:
- Weeks or months to heal – larger area
Third-Degree Burn
Leading cause of accidental death – full thickness burns
Factors:
- Destroy epidermis, all of the dermis, some of the subcutaneous tissue
Healing:
- Can only heal from the edges – large areas often need skin grafts
